Universal behavioural patterns behind the demise of the commons

The difficulty in supervising and controlling common-pool resources emphasizes the need for their sustainable exploitation. Nonetheless, sustainability is often disregarded in favor of overexploitation. To uncover human behavioral patterns when tasked with managing a common-pool resource, we designed and performed a social dilemma experiment combining theoretical and empirical methods. Specifically, we set up a forest dynamics model driven by inputs from volunteers playing a variant of a Public Goods Game. Resources dynamics is modeled in such a way that there is an optimal –in terms of profit- exploitation level while the system is still sustainable. On the contrary, if a threshold is surpassed, the system is unsustainable and resources go extinct. Therefore, during the experiment, whenever participants decide to harvest unsustainably the common-pool is depleted and they achieve lower profits.

We performed the experiment in two different countries, Spain and China. Out of 15 Spanish and 16 Chinese 6-player groups, only one group from each country found the forest's maximum sustainable yield. All the other groups were overzealous, with seven Spanish and one Chinese group surpassing even the no-recovery threshold. Model statistics for subjects from both nations are nearly indistinguishable despite the differences in the outcome. It suggests that participants decisions are mostly controlled by a strong auto-correlative component. On the other hand, the forest state in the previous time step and the decisions of other players has a minor influence over subjects' inputs, revealing a form of "decision-making inertia''. Our results imply that the demise of common-pool resources is due to universal behavioral patterns robust to confounding factors such as culture, education, and age.